Sewing machine



Jan. 4,1927. 1,613,130

a. R. ROBINSON SEWING MACHINE Original Filed June 14, 1918 7 4% 1'??? I r 3 6 f4 60 54 \5 a I ea 50 v I 0/ V I 44 Zz j g 36 i I. .H, u; 43

Incentar q (mmaxvbmknm Patented Jan. 4-, 1927.

Ltllhldd GEORGE E. ROBINfiON, OF BEVERLY, If/IASEaACI'I'USETT-S, ASSLiG'N'OB T UNITED SHOE MACHINERY CGRPOEATIGN, O33 PAIEESON, J'EI tfifiEY, A. CQRPOEATION OF NEW J EBSEY.

SEWING IvLkCHIIIE.

Application filed. .T-une '14, 1918, Serial No. 239,921.

The invention relates to sewing machines and more particularly to presser toot mechanism for such machines.

Although applicable to other machines 5 the invention is particularly designed for application to machines of the class employed in sewing outsoles to the welts of welt-ed shoes. In this class of machines the presser toot mechanism is constructed to lock the presser toot in work clamping toot locking means for this type of presser toot mechanism. To this end the presser foot locking means comprises cooperating looking members which are free to accompany the presser toot in its work clamping movement but look against movement in the opposite direction under pressure transmitted thereto from the presser toot, and one of which is independently movable in the latter direction to unlock the presser foot. The cooperating locking members are preferably in the form of two endwise movable wedge blocks, one of which is connected to the presser toot and the other of which is normally held in engagement with the first by a spring forcing it in a direction to apply the presser foot to the work. The wedge blocks are mounted between fined contact surfaces which diverge in the direction of movementot the blocks in applying the foot to the work so that the blocks are free to move in this direction and thus accommodate themselves to the work engaging position of the presser foot while any pressure transmitted to them from the presser foot and tending to move them in the opposite direction is immediately resisted by the wedging of the blocks between the contact surfaces, the contacting surfaces between the blocks being inclined to both fixed surfaces. The blocks are, therefore, tree to accompany the presser foot in its work clamping move ment and to adjust themselves to its final clamping position and lock against movement in the opposite direction under any lifting pressure applied to the presser foot and transmitted to them therefrom and thus firmly lock the presser foot in any position into which it may be moved in clamping various Renewed February 10, 1922. Serial No. 535,616.

thicknesses 01" work. The spring-pressed l0cking block may be readily moved away from the cooperating block to unlock the presser foot since its independent endwise movement in this direction is resisted merely by the spring which normally maintains it in engagement with the cooperating block. .The TL... v H! LOhtaChlng sui races or the blocks and of the contact plates between which they are arranged may readily be made of sufticient area toavoid any appreciable wear and the parts are self-adjusting so that efiicient and proper operation for an unlimited period of use is practically insured.

A preferred form of the invention is shown in the accompanying drawings .in which Fig. l is a view in side elevation :of a portion 01' an outsole shoe sewing machine embodying the invention, illustrating particularly the prcssentoot mechanism; Fig. 2 1s a view similar to Fig. 1, illustrating certain ot the parts in diiierent positions; and

3 is a detail view partly in side elevation and partly in section illustrating certain parts of the presser-foot mechanism as shown in Fig. 2.

The outsole sewing machine illustrated in the drawings is a machine of the same gen eral t me as that illustrated and described in the patent to Ashworth, No. 1,169,910,

dated February 1, 1916. The machine comprises a curved hook needle 2, a curved work feeding awl 4, a work support 6 and a presser foot 8 of the usual construction which is secured to the forward end of a presser toot lever 10 pivotally mounted on a stud 12. During the action of the stitchtorming devices in forming the stitch the prcsser foot is locked in clamping engagement with the work so that the work is tightly clamped between the presser foot and the work support. During the feeding of the work, however, the presser foot is unlo ked and then rests lightly on the work so 0 offer practically no resistance to the teeding movement of the work. At the end of the feeding movement of the work the presser-foot is pressed into engagement with the work with a comparatively heavy pressure so as to clamp the stock firml against the work-support, and is then locked in position. The presser-foot remains locked until the beginning of the feeding operation, when it is again unlocked, the cycle of operations being repeated.

The means for locking the presser foot comprises two cooperating locking members preferably in the form of two wedge blocks 14 and 22 which are free to accompany the presser foot in its work clamping movement but lock against movement in the opposite direction under lifting pressure applied to the presser foot. The wedge block 14: is connected with the presser foot lever by a pin 16 on the lever which engages a slot 18 in the block. The sur aces of the block diverge upwardly or in the direction of its movement when the presser foot moves towards the work, and one face is arranged to engage the inner surface of a contact plate 20 while the other surface is arranged to engage one surface of the cooperating locking wedge block 7 22. The other surface of the block 22 is arranged to engage the inner surface of a contact guide plate 24: which fits within a slot 26 in the block. The contact surfaces of the plates 20 and 2% diterge upward or in the same direction as the surfaces of the block 14 while the surfaces of the locking block 22 diverge in the opposite direction. The blocks are therefore free to move upward together or in a direction to apply the presser foot to the work but immediately wedge against the contact sur ices if a presser foot lifting or downward pressure is applied to the block it. The locking block 22 may however be readily withdrawn in a downward direction to unlock the presser foot. This block is acted upon by a comparatively heavy spring 32 interposed between a fixed bracket 34 and the lower end of the block. This endwise pressure applied to the locking block is transmitted directly to the block 14 and through it to the presser foot lever and since the upwardly diverging contact surfaces do not obstruct the upward movement of the blocks the presser foot is forced against the work with a heavy pressure to clamp it in position on the work support.

When the locking wedge block is in looking position any tendency to lift the presser foot and thereby to move the block 14 clownwardly will greatly increase the pressure of the rear face of said wedge block against the forward face of the plate 20, the pressure of the forward face of said wedge block against the rear face of the locking wedge block 22 and the pressure of the locking wedge block against the rear face of the guide plate 24:. The frictional resistance of these contacting faces is sufficient to hold the presser-foot locked securely in clamping engagement with'the work. The locking wedge block is held by the coiled spring 32 in locking position during the greater part of each cycle of operations of the machine. Just before the work is fed, however, the locking wedge block is depressed against the action of said coiled spring, as shown in Fig. 2. The depression of the locking wedge block releases the same from forcible engagement with the wedge block 14, so that the latter wedge block is then free to move downwardly and the presser-foot is relieved from clamping engagement with the work. The presser-foot is then preferably held lightly in engagement with the work by the action of a light spring 35 and offers practically no resistance to the feeding of the work between the pressed-f0ot and work support, the presserfoot being allowed to accommodate itself to variations in the thickness of the work. When the feeding of the work has been completed the locking wedge block 22 is again moved upwardly by theaction of the coiled spring 32 thereby, through its action on the wedge block 14, forcing the. presser-foot firmly into engagement with the work and locking the same in position.

The mechanism for thus actuating and controlling the wedge block 22 comprises a rod 3, having its lower end pivoted at 88 to the upper end of the locking wedge block.

A sleeve do is mounted for longitudinal movement on the rod 86 and is formed with spaced projections, or ears 42, between which is pivoted on a stud 44k a gripping arm 46 formed on a block 48, the rear end of which arm operates in an opening in the sleeve 40,

and is arranged to engage a flat face formed.

on the rod 36. The block 48 is pivotally connected at 50 with the end of the forwardly extending arm of a cam lever 52 pivoted on a stud 5a, the rear arm of which lever carries a cam roll 56 engaging in a cam groove in a cam disk 58 secured to the main shaft 60 of the machine. A coiled spring 62 surrounding the rod 36 is interposed between an enlargement, or head, 6 formed on the lower end of the rod and the sleeve 40, which tends to move the sleeve upwardly relatively to the rod. The upward movement of the sleeve is limited by means of a stop projection 65 formed on a plate 66 secured to the frame of the machine, the stop projection being arranged to en age the upper end of the sleeve. The upward movement of the block 4-8 about the pivot stud 4a is limited by the engagement of a projection 68 formed on the block with the sleeve 40. The operation of the mechanism for actuating and controlling the wedge block 22 is as follows:

When the forward arm of the cam lever 52 is in its uppermost position the upper end of the sleeve 40 is held in engagement with the stop projection 65 by the action of the coiled spring 62, the projection 68 on the block 48 is engaged with the sleeve 40, and the inner end of the arm 46 is out of contact with the rod 35, as shown in Fig. 1. The locking wedge block 22 is then held in its upper limiting, or locking, position by the action of the coiled spring 32, the coiled spring 62 which then tends to move the rod Int) 36, and the locking wedge block downwardly, being very light as compared with the spring 32. When the forward arm of the cam lever 52 is swung downwardly the block 48 is first swung downwardly about the pivot stud 44 until the lower portion of the inner end of the arm 46 grips the rod 36, after which the block 4-8, the sleeve 40 and the rod 36 are moved downwardly together, thereby depressing the locking wedge block. As the forward arm of the cam lever 52 swings upwardly, the-inner end of the arm 46 is held in gripping engagement with the rod 36 until the upper end of the sleeve 40 engages the stop projection 65, after which the block 48 swings upwardly about the stud 44:, thereby releasing the inner end of the arm 46 from engagement with the rod 36. The release of the rod 36 allows the locking wedge block 22 to be actuated by the coiled spring 32, to force the presser-foot firmly into engagement with the work and to lock the same in position. With this mechanism for actuating and controlling the .locking wedge block 22, the wedge block is moved a relatively slight uniform distance during each cycle of operations of the machine to unlock the pressenfoot regardless of the locking position of the locking wedge block which varies with variations in the position of the presserfoot due to changes in the thickness of the work.

The presser foot mechanism above described is comparatively simple in construction, .is certain and reliable in its operation, and is strong and durable. The wedge blocks and contact plates have relatively large areas of contact and are therefore not subject to excessive wear. It is also to be noted that these parts are self-adjusting to take up wear and that they will operate in a reliable manner even when they become somewhat worn by use.

Having explained the nature and object of the invention, and having "specifically described a mechanism embodying the invention in its preferred form, what is claimedis:

1. A sewing machine having, in combination, a presser foot and presser foot locking means comprising two contacting wedge blocks, the outer surfaces of which diverge in the direction of their movement .in applying the foot to the work and the contacting surfaces of which are inclined to said outer.

surfaces.

2. A sewing machine having, in combination, a presser foot and presser foot locking means comprising a wedge block connected with the foot, the surfaces of which diverge in the direction of its movement in applying the foot to the work, a cooperating locking wedge block, the surfaces of which diverge in the opposite direction, and fixed contact surfaces between which the blocks are mounted.

3. A sewing machine having, in combination, stitclrzforining devices, a work support, a presser foot, a locking wedge block movable endwise with the presser foot in its work engaging movement, and means for moving the block endwise to lock and unlock the presser foot.

4. A sewing machine having, in combination, stitch forming devices, a wer'k support, a presser foot, an endwise movable locking wedge block, a spring tending to force the block endwise, connections through which the endwise pressure on the block is transmitted directly to the presser foot, and means for moving the block against the tension of the spring to unlock the presser foot.

5. A sewing machine having, in combination, stitch forming-devices, a work support, a presser foot and cooperating presser foot locking members freely movable with the presser foot in its work clamping movement and locking against movement in the opposite direction under pressure trans mitted thereto from the presser foot.

6. A sewing machine having, in combination, stitch forming devices, a work sup- ;port, a presser foot and presser foot locking means comprising two cooperating members freely movable together in :a direction to apply the presser foot to the work and im- L movable in the opposite direction .under pressure transmitted thereto from the presser foot.

7. A sewin machine having in combinar: can tion, stitch forming devices, a work sup port, a presser foot and presser foo t locking means comprising two-cooperat nq looking members mounted iifor free movement together under pressure appliedto one men-- her and immovable in the opposite direction under pressure transmitted from the preser foot to the other member, and means for moving the first member in the latter direc tion to unlock the presser foot.

8. A sewing machine having, incombi'nation, stitch forming devices, a work support, a presser foot and presser foot locking means comp-rising a member connected to move with "the presser foot, a cooperating wedge block mounted for free endwise movement with the member in a direction to apply the presser foot to the work and to lock said member against movement in the opposite direction :under pressure transmitted thereto from the presser foot.

9. A sewing machine having, in combination, stitch forming devices, a work support, a presser foot, a presser foot carrier, a wedge block having converging surfaces, and connections between the same and the presser foot carrier, a locking wedge block for engaging the first wedge block having oppositely converging surfaces, means for moving the locking wedge block to lock and unlock the carrier.

10. A sewing machine having, in combination, stitch forming devices, a work sup port, a presser foot, and two relatively movable cooperating wedge shaped blocks acting to lock and unlock the presser foot during each cycle of operations.

11. A sewing machine having, in combinat'ion, stitch forming devices, a work support, a presser foot, a presser foot carrier, a wedge block and connections between the same and the presser foot carrier, a locking wedge block for engaging the first we block, a contact plate for engaging the ii wedge block against which the first wedge block tends to he forced by any tendency to lift the presser foot when the locking wedge block is in locking position, and means for moving the locking wedge block to lock and unlock the first wedge block.

7 12. A sewing machine having, in combination, stitch forming devices, a' work support, a presser foot, a presser foot carrier, a wedge block and connections between the same and the presser foot carrie, a locking wedge block for engaging the first wedge lock, a contact plate for engaging the look ing wedge block against which the locking wedge block tends to be forced by any tendency to lift the presser foot when the looking wedge block is in locking position, and means for moving the locking wedge block to lock and unlock the first wedge block.

13. A sewing machine having, in combination, stitch forming devices, a work support, a presser foot, a presser foot carrier, a wedge block, and connections between the same and the presser foot carrier, a locking wedge block for engaging the first wedge block, contact plates for engaging the respective wedge blocks arranged so that the wedge blocks tend to be forced against the contact plates by any tendency to lift the presser foot when the locking wedge block is in locking position, and means for moving the locking wedge block to lock and unlock the first wedge block.

let. A sewin machine having, in combination, stitch forming devices, a work support, a presser foot, a presser foot carrier, a wedge block and connections between the same and the presser foot carrier, a locking wedge block for engaging the first wedge block, and angularly arranged plates for engaging the respective wedge blocks, the

contact faces of said plates converging in the direction in which the first wedge block tends to be moved by any tendency to lift the presser foot, and means for moving the locking wedge block to lock and unlock the first wedge block.

15. A sewing machine having, in combination, stitch forming devices, a work support, a presser foot, a presser foot carrier, a locking wedge block arranged to act on the carrier to lock the presser foot in workengaging position, and varying in its looking position with variations in the positions of the presser foot and carrier, a spring through which the locking wedge block is actuated in a direction to lock the carrier,

and means for moving the wedge block a uniform distance from its locking position during each cycle of operations to unlock the carrier.

16. A sewing machine having, in combination, stitch forming devices, a work support, a presser foot, a presser foot carrier, a wedge block having lateral faces arranged at an acute angle to each other, connections between the carrier and the wedge block, a locking wedge block for engagement with the first wedge block, guide plates for engagement with the respective wedge blocks having contact faces converging in the same direction as the lateral faces of the first wedge block and arranged at a less angle to each other than said faces of the first wedge block, and means for moving the locking wedge block to lock and unlock the first wedge block.

17. A sewing machine having, in combina ion, a presser foot, presser foot locking means comprising a wedge block connected with the presser foot, a locking wedge block for engaging the first wedge block on a plane inclined to the direction of movement of both blocks, and means for moving the locking wedge block to lock and unlock the presser foot.

18. A sewing machine having, in combination, a presser foot, presser foot locking means comprising relatively movable cooperating wedge blocks arranged to contact with each other on a plane inclined to the direction of movement of both blocks, and means for relatively moving the blocks to unlock the presser foot.

GEORGE R. ROBINSON. 

